What's the plural form of hypocomplementaemia? Here's the word you're looking for.
Answer
The noun hypocomplementaemia can be countable or uncountable.
In more general, commonly used, contexts, the plural form will also be hypocomplementaemia.
However, in more specific contexts, the plural form can also be hypocomplementaemias e.g. in reference to various types of hypocomplementaemias
or a collection of hypocomplementaemias.